Fuzzy Logic and Genetic-Based Algorithm for a Servo Control System.

Performing control is necessary for processes where a variable needs to be regulated. Even though conventional techniques are widely preferred for their implementation, they present limitations in systems in which the parameters vary over time, which is why methods that use artificial intelligence algorithms have been developed to improve the results given by the controller. This work focuses on implementing a position controller based on fuzzy logic in a real platform that consists of the base of a 3D printer, the direct current motor that modifies the position in this base, the power stage and the acquisition card. The contribution of this work is the use of genetic algorithms to optimize the values of the membership functions in the fuzzification of the input variables to the controller. Four scenarios were analyzed, in which the trajectory and the weight of the system were modified. The results obtained in the experimentation show that the rising and setting times of the proposed controller are better than those obtained by similar techniques that were previously developed in the literature. It was also verified that the proposed technique reached the desired values even when the initial conditions in the system changed.

Terapia hormonal en la transición femenino a masculino (ftm), androgénica, para trans masculino o para hombre transgénero / Hormone Therapy in Female to Male Transition (FTM), Androgenic, Trans Male, or Transgender Male

RESUMEN La transexualidad, o el ser transgénero según la nomenclatura actual, describe a personas que persistentemente buscan ser aceptados como miembros del sexo opuesto, desean cambiar sus caracteres sexuales primarios y/o secundarios a través de intervenciones médicas tanto hormonales como quirúrgicas para feminizarse o masculinizarse. (Tabla 1) Esta discordancia entre su "sexo biológico" y "psicológico" genera estrés clínicamente significativo con rechazo profundo al cuerpo del sexo anatómico, al género asignado al nacer y, por ende, alteración persistente en el funcionamiento diario (mayor a 6 meses), se denomina disforia de género, sienten que nacieron en el "cuerpo equivocado". El objetivo de la intervención médica es mejorar la disforia de género y, por consiguiente, mejora el bienestar y la calidad de vida de las personas trans. En Revista de la Sociedad Chilena de Obstetricia y Ginecología Infantil y de la Adolescencia, recientemente hemos publicado dos artículos de revisión sobre la introducción a la Hormonoterapia en personas transexuales, objetivos de la terapia, transición en la adolescencia, y la transición masculino a femenino, por lo que éste escrito se concentrará sólo en la Terapia Hormonal de la transición femenino a Masculino (FTM), son personas que transitan de Mujer a Hombre, o transgénero masculino o trans masculino. (1,2)

ABSTRACT Transsexuality, or being transgender according to the current nomenclature, describes people who persistently seek to be accepted as members of the opposite sex, wish to change their primary and / or secondary sexual characteristics through both hormonal and surgical medical interventions to feminize or masculinize themselves. (Table 1) This discordance between their "biological" and "psychological" sex, generates clinically significant stress with profound rejection of the body of the anatomical sex, the gender assigned at birth and, therefore, persistent alteration in daily functioning (more than 6 months), is called gender dysphoria feel that they were born in the "wrong Body". The goal of medical intervention is to improve gender dysphoria and, consequently, improve the well-being and quality of life of transgender people. In the Journal of the Chilean Society of Obstetrics and Child and Adolescent Gynecology, we have recently published two review articles on the introduction of Hormonotherapy in transgender people, goals of therapy, transition in adolescence, and the male-to-female transition, so this paper will focus only on Hormonal Therapy of the female to male transition (FTM), are people who transit from woman to man, or male trans, male transgender. (1,2)

Where is the enigmatic Telmatobius halli Noble 1938? Rediscovery and clarification of a frog species not seen for 80 years.

Telmatobius halli was the first endemic Telmatobius species described in Chile, reported by Noble in 1938 near the locality of Ollagüe, in the high Andean zone of the Antofagasta region. To this date, there are no specimens assignable to this species other than the type series; although many expeditions have tried to search for T. halli, they have been unsuccessful, but they have found and described new species around this area. In order to clarify the origin of the enigmatic T. halli, we reviewed the itinerary of the expedition carried out by F. G. Hall in the Chilean Altiplano, to place a putative type locality. We contrast the morphology of the holotype, with that of recently collected specimens from the new putative type locality, to confirm the population's identity; and finally, we perform phylogenetic analyses in order to clarify the systematic position of this taxon. The historical review of the expedition that collected these frogs shows that it is likely that Telmatobius halli had been collected near Collahuasi, about 50 km northwest of Ollagüe, site that we have assigned as a putative type locality for T. halli. The morphological analyses support this hypothesis, while phylogenetic results show that the specimens assigned to this species form a monophyletic group, and is a sister clade of T. chusmisensis. Thus, we propose that the type locality of T. halli be changed from "around Ollagüe" to the area of the Copaquire ravine, so its distribution would be restricted to this system and Choja-Chijlla ravine, both in the high Andean zone of the Región de Tarapacá, Chile.

Tasa de cesáreas según la clasificación de Robson: análisis comparativo entre dos hospitales universitarios / Tasa de cesáreas según la clasificación de Robson: análisis comparativo entre dos hospitales universitarios

RESUMEN Introducción y objetivos: La ejecución de cesáreas para la interrupción del embarazo y su tasa óptima de utilización ha sido un tema controversial desde sus inicios. En esta línea Robsons y Cols proponen una clasificación para evaluar y comparar de manera eficaz las prácticas realizadas en las distintas instituciones de salud. El objetivo de este trabajo fue comparar la tasa de cesáreas realizadas durante el año 2017 tanto en el Hospital Clínico Universidad de Chile (HCUCH) como en el Hospital base San José de Osorno (HBSJO), y de esta forma, describir sus diferencias estadísticas. Métodos: Los resultados se obtuvieron mediante la recopilación de datos del libro de pabellones disponible en ambos departamentos. Resultados: Se observó una diferencia significativa en la interrupción del embarazo vía alta, la que alcanzó un 55,7% en el HCUCH, en contraste con un 35,7% en el HBSJO. En el HCUCH, el 87,8% de la totalidad de los partos correspondieron a mujeres con embarazos de bajo riesgo, realizándose cesárea en el 52,9% de ellas. En el HBSJO en cambio, las cifras fueron de un 74,6% y 32,2% respectivamente. En las únicas categorías en las cuales no existió una diferencia estadísticamente significativa en cuanto a la tasa de cesáreas realizadas fueron las distocias de presentación y los embarazos gemelares, alcanzando un a tasa de 100% en embarazos gemelares en el HBSJO. Las hipótesis que explican estas diferencias radican principalmente en la organización administrativa y a la población atendida en cada hospital. Conclusiones: Los distintos centros asistenciales de nuestro país se rigen por distintas formas de funcionamiento. Esto explica entre otras cosas, la diferencia estadísticamente significativa que se produce al comparar la tasa de cesárea del HCUCH con el HBSJO. Hacemos un llamado en este trabajo a utilizar el método de clasificación de Robson para facilitar la supervisión y la comparación crítica de estos índices en los hospitales.

ABSTRACT Introduction and objectives: The caesarean section execution for the interruption of pregnancy and its optimal rate of use, has been a controversial issue since its inception. In this line Robsons and Cols propose a classification to standardize and effectively compare the practices carried out in the different health institutions. The aim of this study was to compare the rate of cesareans performed during 2017 both at the "University Clinical Hospital of Chile" (HCUCH) and at the "San José de Osorno Hospital" (HBSJO), and in this way, describe their statistical differences. Methods: The results were obtained by collecting data from the pavilion book available in both departments. Results: There was a significant difference in the cesarean rate between both hospitals. This difference reached 55.7% in the HCUCH, in contrast to 35.7% in the HBSJO. In the HCUCH, 87.8% of all the deliveries corresponded to women with low risk pregnancies, with cesarean sections performed in 52.9% of them. On the other hand, in the HBSJO the values were 74.6% and 32.2% respectively. The only categories in which there was no statistically significant difference in the rate of cesarean sections performed, were pregnancies with dystocia presentation and twin pregnancies, reaching a 100% of surgical intervention in this last group. The hypotheses that explain these differences lie mainly in the administrative organization and the population served in each hospital. Conclusions: The different healthcare centers in our country are governed by different ways of functioning. This explains, among other things, the statistically significant difference that occurs when comparing the cesarean rate of the HCUCH and the HBSJO. We encourage in this study to use Robson's classification method to facilitate the supervision and critical comparison of these indices in hospitals.

Terapia hormonal en persona transgénero según world professional association for transgender health (WPATH) () y guías clinicas de la endocrine society. () / Hormone therapy in transgender person according to world professional association for transgender health (WPATH) and clinical guidelines of the endocrine society

RESUMEN La identidad de género es la percepción intrínseca de una persona de ser hombre, mujer o alguna alternativa de género. Las personas transgénero perciben estar en un cuerpo equivocado, ya que se sienten del sexo opuesto al biológico. Cuando esta incongruencia entre identidad de género y el fenotipo físico del sexo asignado, genera gran angustia, ansiedad y malestar persistente, se denomina disforia de género. Se estima que el 0,4%- 1.3% de la población mundial experimentan distintos grados de Disforia de Género. (3), no todas las personas con disforia de género tienen las mismas necesidades, por lo que la evaluación del objetivo personal para lograr bienestar es muy importante. Todas las intervenciones médicas conllevan riesgos, por lo que, la comprensión de éstos últimos, la adherencia y el manejo por profesionales capacitados los minimiza. En Revista de la Sociedad Chilena de Obstetricia y Ginecología Infantil y de la Adolescencia, recientemente hemos publicado dos artículos de revisión sobre la introducción a la Hormonoterapia en personas transgénero, objetivos de la terapia, transición en la adolescencia, y la transición masculino a femenino, por lo que éste escrito se concentrará sólo en los Riesgos de la Terapia Hormonal en la transición. (4,5)

SUMMARY Gender identity is the intrinsic perception of a person to be a man, woman or some gender alternative. Transgender people feel that they are in the wrong body, since they feel the opposite sex to the assigned. When this incongruence between gender identity and the physical phenotype generates great anguish, anxiety and persistent discomfort, it is called gender dysphoria. It is estimated that 0.4% −1.3% of the world population experience different degrees of Gender Dysphoria. (3), and not all people with gender dysphoria have the same needs, so the evaluation of the personal goal to achieve well-being is very important. All medical interventions involve risks, so the understanding of the latter, adherence and management by trained professionals minimizes them. In the Journal of the Chilean Society of Obstetrics and Child and Adolescent Gynecology, we have recently published two review articles on the introduction to Hormonotherapy in transgender people, objectives of therapy, transition in adolescence, and the male to female transition, so this writing will focus only on the Risks of Hormonal Therapy in the transition. (4,5)

The taxonomic status of two Telmatobius frog species (Anura: Telmatobiidae) from the western Andean slopes of northernmost Chile.

On the basis of molecular and morphological evidence, we evaluated the taxonomic identity of two species of Andean frogs of the genus Telmatobius: Telmatobius pefauri and T. zapahuirensis, present in the western Andean slopes at the northern extreme of Chile. We also investigated the taxonomic assignment of five populations of Telmatobius recently discovered around the type localities of these two species. The results indicate that T. pefauri inhabits, not only Murmuntani its type locality, but also the montane localities of Belén, Copaquilla, Lupica, Saxamar and Socoroma. Our study also shows that T. pefauri and T. zapahuirensis are the same taxon. Therefore, Telmatobius zapahuirensis Veloso, Sallaberry, Navarro, Iturra, Valencia, Penna & Díaz, 1982 would be a subjective junior synonym of Telmatobius pefauri Veloso & Trueb, 1976.

Genotyping and Persistence of Candida albicans from Pregnant Women with Vulvovaginal Candidiasis.

OBJECTIVE: To study Candida albicans genotypes using RAPD and their susceptibility to fluconazole in healthy pregnant women and in vulvovaginal candidiasis (VVC) patients after topical treatment with clotrimazole. METHODS: Vaginal swabs were collected at t = 0 and t = 1 (1 month later) in pregnant women (control group, n = 33), and before (t = 0), at 1 month (t = 1) and at 2 months (t = 2) after clotrimazole treatment in pregnant women with VVC. RESULTS: Candida albicans was isolated in 30% of healthy pregnant women and 80% of patients with VVC. A high genetic heterogeneity was observed in C. albicans genotypes between individuals. In patients with VVC, topical antifungal treatment with clotrimazole was clinically effective, but only in a 62% C. albicans was eradicated. In patients in which C. albicans was not eradicated, this microorganism persisted for 1 or 2 months after the antifungal treatment. The persistent colonies were not associated with a specific genotype, but they were associated with higher MICs in comparison with colonies isolated from the control group. CONCLUSIONS: Therapy with topical clotrimazole, despite a good clinical outcome, could not eradicate completely C. albicans allowing the persistence of genotypes, with higher MICs to fluconazole. More studies with higher number of patients are needed to validate this preliminary finding.

Evolution and Conservation on Top of the World: Phylogeography of the Marbled Water Frog (Telmatobius marmoratus Species Complex; Anura, Telmatobiidae) in Protected Areas of Chile.

The Andean Altiplano has served as a complex setting throughout its history, driving dynamic processes of diversification in several taxa. We investigated phylogeographic processes in the Telmatobius marmoratus species complex occurring in this region by studying the geographic patterns of genetic variability, genealogies, and historical migration, using the cytochrome b (cyt-b) gene as a marker. DNA sequences from Telmatobius gigas and Telmatobius culeus, Bolivian species with an uncertain taxonomic status, were also included. Additionally, we evaluated the phylogenetic diversity (PD) represented within Chilean protected areas and the complementary contribution from unprotected populations. Phylogenetic reconstructions from 148 cyt-b sequences revealed 4 main clades, one of which corresponded to T. culeus. T. gigas was part of T. marmoratus clade indicating paraphyletic relationships. Haplotypes from Chilean and Bolivian sites were not reciprocally monophyletic. Geographic distribution of lineages, spatial Bayesian analysis, and migration patterns indicated that T. marmoratus displays a weaker geographic structure than expected based on habitat distribution and physiological requirements. Demographic and statistical phylogeography analyses pointed out to a scenario of recent population expansion and high connectivity events of a more recent age than the post Last Glacial Maximum, probably associated to more humid events in Altiplano. PD of T. marmoratus populations within protected areas represents 55.6% of the total estimated PD. The unprotected populations that would contribute the most to PD are Caquena and Quebe (21%). Recent evolutionary processes and paleoclimatic changes, potentially driving shifts in habitat connectivity levels and population sizes, could explain the phylogeographic patterns recovered herein.

[Nugent and Spiegel criteria for the diagnosis of bacterial vaginosis. Analysis of discordant specimens by the Ison and Hay method]. / Comparación de los criterios de Nugent y Spiegel para el diagnóstico de vaginosis bacteriana y análisis de los resultados discordantes por el método de Ison y Hay.

BACKGROUND: Vaginal infection is the commonest cause of genital symptoms and has obstetric and gynecological implications. AIM: To compare the Nugent and Spiegel methods for the diagnosis of bacterial vaginosis (BV) and to analyze discordant specimens using Ison and Hay (Ison/Hay) criteria. MATERIAL AND METHODS: After discarding cases with Candidiasis, deficient specimens or those lacking bacteria, a total of 348 Gram-stained smears vaginal specimens received for the diagnosis of BV, were analyzed. RESULTS: Vaginal microbiota was classified as normal in 203 and 237 samples (58 and 68% of samples), according to Nugent and Spiegel criteria, respectively One hundred and five (30%) and 111 samples (32%), were classified as VB according to Nugent and Spiegel criteria, respectively. Both criteria were concordant in 308 samples (88.5%). The 40 (11.5%) discordant specimens were classified as intermediate microflora by the Nugent system and as normal or BV by Spiegel. Among these, the Ison/Hay procedure identified four categories of microbiota. Ten (25%) specimens were classified as grade II microbiota, confirming their categorization by Nugent as intermediate microbiota, six (15%) were classified in the III category, confirming the diagnosis of BV by Spiegel, 13 (32.5%) corresponded to the category III, that does not exist in the Nugent and Spiegel categorization systems. Finally, 11 specimens could not be assigned to one category due to microscopic limitations to distinguish bacterial morphotypes. CONCLUSIONS: The systems proposed by Spiegel, Nugent and Ison/Hay are comparable for the diagnosis of BV. However, we recommend the use of Ison/Hay procedure to evaluate vaginal microbiota, due to its wider range of categories, allowing a better discrimination of the vaginal microbiota.

Comparación de los criterios de Nugent y Spiegel para el diagnóstico de vaginosis bacteriana y análisis de los resultados discordantes por el método de Ison y Hay / Nugent and Spiegel criteria for the diagnosis of bacterial vaginosis. Analysis of discordant specimens by the Ison and Hay method

Background: Vaginal infection is the commonest cause of genital symptoms and has obstetric and gynecological implications. Aim: To compare the Nugent and Spiegel methods for the diagnosis of bacterial vaginosis (BV) and to analyze discordant specimens using Ison and Hay (Ison/Hay) criteria. Material and Methods: After discardingcases with Candidiasis, deficientspecimens or those lacking bacteria, a total of348 Gram-stained smears vaginal specimens receivedfor the diagnosis of BV, were analyzed. Results: Vaginal microbiota was classified as normal in 203 and 237 samples (58 and 68 percent of samples), accordingto Nugent and Spiegel criteria, respectively One hundred andfive (30 percent) and 111 samples (32 percent), were classified as VB accordingto Nugent and Spiegel criteria, respectively. Both criteria were concordant in 308 samples (88.5 percent). The 40 (11.5 percent) discordant specimens were classified as intermedíate microflora by the Nugent system and as normal or BV by Spiegel. Among these, the Ison/Hay procedure identified four categories of microbiota. Ten (25 percent) specimens were classified as grade II microbiota, confirming their categorization by Nugent as intermedíate microbiota, six (15 percent) were classified in the III category, confirming the diagnosis ofBV by Spiegel, 13 (32.5 percent) corresponded to the category III, that does not exist in the Nugent and Spiegel categorization systems. Finally, 11 specimens could not be assigned to one category due to microscopic limitations to distinguish bacterial morphotypes. Conclusions: The systems proposed by Spiegel, Nugent and Ison I Hay are comparable for the diagnosis of BV. However, we recommend the use of Ison/ Hay procedure to evalúate vaginal microbiota, due to its wider range of categories, allowing a better discrimination ofthe vaginal microbiota.

Trombosis de vena ovárica y vena cava inferior asociada a endometritis en el puerperio / Ovarian and inferior vena cava thrombosis with associated puerperal endometritis

La trombosis de vena ovárica es una complicación infrecuente y grave del puerperio. Suele presentarse como fiebre y dolor abdominal o pélvico en el puerperio, más frecuentemente en cesáreas. Existe un riesgo alto de tromboembolismo pulmonar y requiere un diagnóstico y tratamiento tempranos. Presentamos el caso de una paciente de 30 años, puérpera, con un cuadro de dolor pélvico y fiebre. Se realizó una tomografía computada y se detectó una trombosis de la vena ovárica derecha con extensión a la vena cava inferior. Se diagnosticó además endometritis, se trató con dalteparina y antibióticos. La trombosis de vena ovárica es un diagnóstico diferencial importante de fiebre en el puerperio (AU)

Ovarian vein thrombosis is a rare and severe puerperal complication that usually manifests as fever and abdominal pain in the puerperal period and is more frequent in women who have undergone cesarean section. There is an associated high risk of pulmonary embolism and thus early diagnosis and treatment are required. We report the case of a 30-year-old woman with pelvic pain and fever in the puerperal period. Computed tomography scan revealed ovarian vein thrombosis extending to the inferior vena cava. Endometritis was also diagnosed. The patient received dalteparin and antibiotics. Ovarian vein thrombosis should be included in the differential diagnosis of fever in the postpartum period (AU)

Estudio de la dinámica de servicios hospitalarios mediante la utilización de técnicas estadísticas multivariables: el caso del Hospital Clínico de la Universidad de Chile / Study of hospital activity through the use of multivariate statistical tecniques: the case of the Hospital Clínico de la Universidad de Chile

Objetivo: Obtener indicadores útiles y dinámicos para la gestión hospitalaria mediante análisis de componentes principales. Material y método: Se analizó la información del Hospital Clínico de la Universidad de Chile correspondiente a la actividad de los servicios medicoquirúrgicos desde enero de 2003 a diciembre de 2004. Las variables analizadas fueron: número de altas, tasa de letalidad, tasa de reingresos, número de consultas externas, número de días de camas ocupadas e índice de complejidad quirúrgica. Aplicamos la técnica de análisis de componentes principales (ACP), y se utilizó la matriz de correlaciones R. Resultados: Se seleccionaron los primeros 2 componentes para cada año, que dieron cuenta del 75,92% de la variabilidad en los datos: el 47,02% el primero y el 28,9% el segundo. El primer componente se puede interpretar como un nuevo índice relacionado con la complejidad asistencial y el segundo, con la demanda asistencial. Conclusiones: La utilización de estos nuevos indicadores permitiría categorizar los servicios hospitalarios y supervisar su rendimiento, lo que facilitaría la implementación de medidas de corrección

Objective: To obtain useful hospital management indicators, based on the technique of principal components analysis. Material and method: We analyzed information on the activity of medical-surgical services in the Hospital Clinico de la Universidad de Chile from January 2003 to December 2004. The following variables were analyzed: number of discharges, lethality rate, readmissions rate, number of outpatient consultations, number of hospital stays, and the surgical complexity index. The principal components analysis (PCA) technique was applied and the R correlation matrix was used. Results: The first two principal components for each year were selected, accounting cumulatively for 75.92% of the variability in the data: 47.02% for the first and 28.90% the second. The first component may be interpreted as a new index related to clinical complexity and the second related to healthcare demand. Conclusions: The use of these new indicators would aid classification of hospital services and performance monitoring, allowing appropriate corrective measures to be introduced

Nueva propuesta de indicadores de gestión de los servicios médico-quirúrgicos mediante técnicas estadísticas multivariantes / New indicators for the management of medico-surgical services based on multivariate techniques

Objetivo: Obtener indicadores útiles para la gestión hospitalaria mediante la utilización de técnicas estadísticas multivariantes descriptivas. Material y método: Durante abril del año 2006 se analizó la información del Hospital Clínico de la Universidad de Chile correspondiente a los egresos hospitalarios del año 2003. Se estudiaron las variables monitorizadas por la Gerencia de Operaciones del Hospital Universitario: número de egresos, tasa de letalidad, tasa de reingresos, número de consultas externas, número de días de camas ocupadas, estadía en unidad de cuidados intensivos, edad de los pacientes e índice de complejidad quirúrgica. Las variables se midieron para un total de 24.345 egresos. Aplicamos la técnica de análisis de componentes principales (ACP), y se utilizó la matriz de correlaciones R. Resultados: Se seleccionaron las primeras 2 componentes, con un porcentaje acumulado de variabilidad del 71,3%: del 49,4%, la primera, y del 21,9%, la segunda. Conclusiones: La primera componente puede ser relacionada a un nuevo índice que tiene que ver con la dificultad de los casos atendidos; lo hemos denominado complejidad asistencial. La segunda explicaría la cuantía de personas atendidas, y denominamos demanda asistencial. Ambos índices nos permiten dar una clasificación de los servicios hospitalarios

Objective: To obtain indicators useful for hospital management based on descriptive multivariate techniques. Material and method: Data on hospital admissions in 2003 were analyzed in April 2006 in the Hospital Clínico de la Universidad de Chile. The variables monitored by the Operations Management Department in the university hospital were studied: number of discharges, mortality rate, re-admissions rate, number of outpatient consultations, number of hospital stays, length of stay in the intensive care unit, patient age, and surgical complexity index. The variables were considered for a total of 24,345 discharges. The principal components analysis (PCA) technique was applied and the R correlation matrix was used. Results: The first two principal components were selected, accounting accumulatively for 71.3% of the variability: the first component for 49.4% and the second component for 21.9%. Conclusions: The first component may be related to a new index representing the complexity of the patients attended, which we have termed Case Complexity. The second principal component would explain the number of persons attended, which we have termed Case Load. These two indices allow us to classify hospital services

Vías alternativas de histerectomía. Experiencia con 2.527 pacientes en el Hospital Clínico de la Universidad de Chile / Alternative routes for hysterectomy. Experience in 2527 patients at the University of Chile’s Clinical Hospital

Objetivo: Evaluar los resultados a corto plazo de 3 técnicas de histerectomía. Material y método: Estudio retrospectivo observacional. El estudio incluye a 2.527 pacientes entre 27 y 86 años, histerectomizadas por enfermedad ginecológica benigna, que fueron atendidas en el Hospital Clínico de la Universidad de Chile entre enero de 1997 y diciembre de 2005. Las variables analizadas fueron de la cirugía propiamente, como tiempo operatorio y complicaciones durante el procedimiento, y del postoperatorio, como las complicaciones postoperatorias, y finalmente se realizó un análisis comparativo de los costos. Para comparar las variables categóricas se usó el test exacto de Fisher y para las variables continuas, la prueba de la t de Student para comparación de 2 medias. Resultados: En cuanto al tiempo operatorio, la histerectomía laparoscópica requirió en promedio 124 min; la abdominal, 119 min, y la vaginal, 98 min, significativamente menor (p < 0,0001). Las complicaciones postoperatorias fueron significativamente más frecuentes en la histerectomía abdominal que en la vía vaginal y más frecuentes en ésta que en la laparoscópica. La estancia hospitalaria fue en promedio 2,7 días para la vía vaginal, 3,1 días para la abdominal y 2,3 días para la laparoscópica, diferencia estadísticamente significativa. El análisis de costos muestra que la vía laparoscópica es más costosa que las otras alternativas quirúrgicas. Conclusiones: Este estudio indica que en nuestro hospital la histerectomía por vía vaginal es menos costosa y muestra menor tiempo operatorio que la laparoscópica. También que ésta exhibe una serie de ventajas respecto a la vía abdominal, con menos complicaciones, tiempo operatorio y estancia hospitalaria

Objective: To evaluate the short-term outcomes of three total hysterectomy techniques. Material and method: We performed an observational retrospective study of 2527 patients aged 27 to 86 years who underwent hysterectomy for benign gynecologic disorders at the University of Chile's Clinical Hospital between January 1997 and December 2005. The variables analyzed were related to the surgery itself (including operating time and intrasurgical complications) and to the postoperative period (including postoperative complications). Finally, a comparative analysis of costs was made. Fisher's exact test was used to compare categorical variables and the t test for comparison of two means was used for continuous variables. Results: Operating time required an average of 124 minutes for total laparoscopic hysterectomy (LH), 98 minutes for vaginal hysterectomy (VH), and 119 minutes for abdominal hysterectomy (AH); the lower operating time required for VH was statistically significant (p < 0.0001). Postsurgical complications were significantly more frequent in AH, followed by VH and finally LH. The mean length of hospital stay was 2.7 days for VH, 3.1 days for AH, and 2.3 days for LH, and this difference was statistically significant. Cost analysis showed that LH was the most expensive procedure, followed by AH and finally VH. Conclusions: This study suggests that in our hospital VH is less expensive than LH. The latter presents some advantages over AH, including include fewer complications, shorter operating times, and shorter hospital stays

[Study of variables associated with skin cancer in Chile using principal component analysis]. / Estudio de variables asociadas al cáncer de piel en Chile mediante análisis de componentes principales.

BACKGROUND: The incidence of skin cancer in Chile has increased in recent years. OBJECTIVE: To associate variables with skin cancer in Chile through indices generated using multivariate descriptive statistical techniques. MATERIAL AND METHOD: During May 2004, information was gathered from demographic, meteorological and clinical data from Chile corresponding to fiscal year 2001, the latest complete, official information available for the country's Health Services as a whole. The variables developed by the following were studied: the National Statistics Institute (INE), the Ministry of Health (MINSAL), the Ministry of Planning and Cooperation (MIDEPLAN), the National Health Fund (FONASA), the Chilean Meteorological Directorate, Federico Santa María Technical University and the Directorate-General for Water. A Principal Component Analysis (PCA) was then performed on the data obtained. RESULTS: The first three principal components were selected, with a cumulative explained variance percentage of 54.48 %. The first principal component explains 24.92 % of the variance, and is related to climatic and geographic variables. The second principal component explains 15.77 % of the variance, and is mainly related to FONASA's beneficiary population and the poverty rate. The mortality rate from skin cancer runs significantly against this component. The third principal component explains 13.79 % of the variance, and is related to population characteristics, such as total catchment population, female population and urban population. CONCLUSION: Performing PCA is useful in studying the factors associated with skin cancer.

Estudio de variables asociadas al cáncer de piel en Chile mediante análisis de componentes principales / Study of variables associated with skin cancer in Chile using principal component analysis

Fundamento. La incidencia de cáncer de piel en Chile ha aumentado en los últimos años. Objetivo. Asociar variables al cáncer de piel en Chile a través de índices generados mediante técnicas estadísticas descriptivas multivariantes. Material y método. Durante el mes de mayo de 2004 se recopiló información de datos demográficos, meteorológicos y clínicos de Chile, correspondientes al ejercicio 2001, última información completa y oficial disponible para la totalidad de los Servicios de Salud del país. Se estudiaron las variables confeccionadas por el Instituto Nacional de Estadística (INE), el Ministerio de Salud (MINSAL), el Ministerio de Planificación y Cooperación (MIDEPLAN), el Fondo Nacional de Salud (FONASA), la Dirección Meteorológica de Chile, la Universidad Técnica Federico Santa María y la Dirección General de Aguas. Se aplicó a los datos obtenidos un análisis de componentes principales (ACP). Resultados. Se seleccionaron las tres primeras componentes principales, con un porcentaje acumulado de variabilidad explicada de 54,48 %. La primera componente principal explica el 24,92 % de la variabilidad y tiene relación con variables del orden climático y geográfico. La segunda componente principal explica el 15,77 % de la variabilidad y se relaciona principalmente con la población beneficiaria de FONASA y el índice de pobreza. En ella se opone de manera importante la tasa de letalidad por cáncer cutáneo. La tercera componente principal explica el 13,79 % de la variabilidad y se relaciona con características poblacionales como población total asignada, población femenina y población urbana. Conclusión. La aplicación del ACP es útil para el estudio de los factores asociados con el cáncer de piel

Background. The incidence of skin cancer in Chile has increased in recent years. Objective. To associate variables with skin cancer in Chile through indices generated using multivariate descriptive statistical techniques. Material and method. During May 2004, information was gathered from demographic, meteorological and clinical data from Chile corresponding to fiscal year 2001, the latest complete, official information available for the country's Health Services as a whole. The variables developed by the following were studied: the National Statistics Institute (INE), the Ministry of Health (MINSAL), the Ministry of Planning and Cooperation (MIDEPLAN), the National Health Fund (FONASA), the Chilean Meteorological Directorate, Federico Santa María Technical University and the Directorate-General for Water. A Principal Component Analysis (PCA) was then performed on the data obtained. Results. The first three principal components were selected, with a cumulative explained variance percentage of 54.48 %. The first principal component explains 24.92 % of the variance, and is related to climatic and geographic variables. The second principal component explains 15.77 % of the variance, and is mainly related to FONASA's beneficiary population and the poverty rate. The mortality rate from skin cancer runs significantly against this component. The third principal component explains 13.79 % of the variance, and is related to population characteristics, such as total catchment population, female population and urban population. Conclusion. Performing PCA is useful in studying the factors associated with skin cancer

Estudio comparativo de variables clínicas y costo de la técnica quirúrgica de histerectomía por vía abdominal y laparoscópica / A comparative study of clinical variables and surgical technique cost between patients treated with either abdominal or laparoscopic hysterectomy

El objetivo de este estudio es comparar los efectos clínicos y económicos de la histerectomía abdominal versus la histerectomía laparoscópica. Es un estudio retrospectivo observacional de 1.163 pacientes de 27 a 83 años histerectomizadas por patología ginecológica benigna durante 1997-2005, en el Hospital Clínico de la Universidad de Chile. De las 1.663 cirugías, el 11,36 por ciento fueron histerectomías laparoscópicas y el 88.63 por ciento correspondió a histerectomías abdominales. La tasa global de complicaciones fue de 42,8 por 100 mujeres para la histerectomía abdominal y 16,4 por ciento para la histerectomía laparoscópica. La histerectomía laparoscópica presenta algunas ventajas al compararla con la histerectomía abdominal. Se asoció a menos complicaciones y menor tiempo de estadía hospitalaria. En contraste, su costo es significativamente mayor.

[A proposal of new indices for hospital management]. / Propuesta de índices de gestión de servicios médico-quirúrgicos hospitalarios mediante técnicas estadísticas multivariantes.

BACKGROUND: Diagnosis related groups (DRGs) are the most reliable patient classification system in hospital management. When this information is unavailable, other reliable classification system must be used. AIM: To obtain useful indices for hospital management, based on descriptive multivariate techniques. MATERIAL AND METHODS: Data on admissions to a University Hospital during 2003 were analyzed. Number of discharges, lethality rate, re-admission rate, number of outpatient consultations, length of hospital stay and surgical complexity index were analyzed, using information obtained by the Operations Management Department. The Principal Components Analysis (PCA) technique was applied and the R correlation matrix was used. RESULTS: A total of 24,345 discharges were analyzed. The first two principal components were selected, accounting cumulatively for 76% of data variability (47% for the first and 29% for the second). CONCLUSIONS: The first component may be assimilated to a new index representing the difficulty of the attended cases, which we have termed Case Complexity. The second principal component would explain the number of attended persons, which we have termed Case Load. These two indices allow us to classify hospital services.

Propuesta de índices de gestión de servicios médico-quirúrgicos hospitalarios mediante técnicas estadísticas multivariantes / A proposal of new indices for hospital management

Background: Diagnosis related groups (DRGs) are the most reliable patient classification system in hospital management. When this information is unavailable, other reliable classification system must be used. Aim: To obtain useful indices for hospital management, based on descriptive multivariate techniques. Material and Methods: Data on admissions to a University Hospital during 2003 were analyzed. Number of discharges, lethality rate, re-admission rate, number of outpatient consultations, length of hospital stay and surgical complexity index were analyzed, using information obtained by the Operations Management Department. The Principal Components Analysis (PCA) technique was applied and the R correlation matrix was used. Results: A total of 24,345 discharges were analyzed. The first two principal components were selected, accounting cumulatively for 76percent of data variability (47percent for the first and 29percent for the second). Conclusions: The first component may be assimilated to a new index representing the difficulty of the attended cases, which we have termed Case Complexity. The second principal component would explain the number of attended persons, which we have termed Case Load. These two indices allow us to classify hospital services.

Diseño e implementación de paquetes asistenciales en el Hospital Clínico de la Universidad de Chile / Design and implementation of diagnosis-related group packages in the Hospital Clínico of the University of Chile

Los sistemas de financiación de los hospitales están considerando de manera creciente el pago por la actividad que estos centros generan, más que el gasto en que éstos incurren independientemente de su actividad. Por tanto, es indispensable el diseño de metodologías que apunten a la adecuada construcción de paquetes de prestaciones. El Hospital Clínico de la Universidad de Chile ha estado elaborando una metodología para construir paquetes asistenciales y evaluar su aplicación en varios servicios clínicos. Se presenta la metodología y su aplicación a las siguientes intervenciones: a) colecistectomía por vía laparoscópica, y b) tonsilectomía a manera de ejemplo, así como la aplicación de ésta como un sistema de auditoría clínica a partir de variables económicas, la cual puede ser complementaria a las que se emplean en el interior de los centros hospitalarios (AU)